Earth Defense (aka: The Earth Defend) is an unlicensed game for the Sega Mega Drive/Genesis; it was developed by AV Artisan and published by Realtec in both North America and Taiwan, without a license from Sega.
The game cartridge and box shapes as well as quality in graphics and box art are identical to AV Artisan's previous titles Funny World & Balloon Boy and Whac-A-Critter, both published by Realtec. Earth Defense was also rare in that it was a simultaneous 2 player vertical scrolling shoot 'em up on the Genesis which primarily featured single player shoot 'em ups. The player takes on the role of a jet pilot assigned to liberate five world continents from a technologically advanced army.
Players had two different types of weapons to choose from during combat. A vulcan/spread shot weapon and a wave/beam shot weapon. Rather than possessing bomb-like items, the players had a shield item that made the ship temporarily invulnerable.